//
// Copyright (C) 2004 Andras Varga
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program; if not, see <http://www.gnu.org/licenses/>.
//



package inet.linklayer.ppp;

//
// \PPP implementation.
//
// Packets are encapsulated in PPPFrame.
//
// \PPP is a complex protocol with strong support for link configuration
// and maintenance. This model ignores those details, and only performs
// simple encapsulation/decapsulation and queuing.
//
// In routers, \PPP relies on an external queue module (see OutputQueue)
// to model finite buffer, implement QoS and/or RED, and requests packets
// from this external queue one-by-one.
//
// In hosts, no such queue is used, so \PPP contains an internal
// queue named txQueue to queue up packets waiting for transmission.
// Conceptually, txQueue is of infinite size, but for better diagnostics
// one can specify a hard limit in the txQueueLimit parameter -- if this is
// exceeded, the simulation stops with an error.
//
// There is no buffering done on received packets -- they are just decapsulated
// and sent up immediately.
//
// @see PPPInterface, OutputQueue, PPPFrame
//
simple PPP
{
    parameters:
        int txQueueLimit = default(1000);  // only used if queueModule==""; zero means infinite
        string queueModule = default("");  // name of external (QoS,RED,etc) queue module
        int mtu = default(4470);
        @display("i=block/rxtx");
    gates:
        input netwIn;
        output netwOut;
        inout phys @labels(ppp);
}


